At the Chief Editor's re- quest, I address some issues raised in the correspondence on ODS.

The DSM-III-R precludes a diagnosis of ODS if the patient is delirious (per criterion C). Organic delusional syndrome and dementia are not mutually exclusive categories in DSM-III-R, although they were in DSM-III. Cornelius et al1 reported that 43.6% of their ODS cases had "impaired sensorium" and 66.7% had "acquired intellectual impairment." The presence of an "impaired sensorium," however mild, strongly suggests delirium rather than ODS as the appropriate diagnosis in those cases. The "acquired intellectual impairment" suggests a probable diagnosis of dementia, which would not preclude a concurrent diagnosis of ODS. Looking to DSM-IV,2 the terms "impairment of consciousness" and "the development of multiple cognitive deficits" (memory impairment and cognitive impairment) are proposed as the "A" criteria of delirium and dementia, respectively.